Continuation support is requested for the remaining years of a specialized Hypertension Center at the Columbia-Presbyterian Medical Center. The approach at this Center is based on specific hormonal and physiologic profiling of hypertensive patients and then individualized antihypertensive drug therapy based on these profiles. Effects on natural history are studied longitudinally. More specifically, recent developments make it possible to classify the large population of so-called "essential" hypertension on the basis of definable abnormalities of the renin-angiotensin-aldosterone system. The information collected so far suggests that this approach has meaningful etiologic, prognostic and pharmacologic correlates. Thus low-renin hypertensive patients appear to be relatively protected from the development of heart attack and stroke perhaps suggesting that they are less urgently in need of antihypertensive drug therapy. Moreover, it has been found that different types of drugs are effective in the different hormonal groups enabling more specific individualized treatment. Antiadrenergic drugs seem most effective in high renin patients. More work is needed to define the effects of combination therapies, especially in the normal renin patients.